Code reader device and recording medium

ABSTRACT

A code reader device, prior to extracting a code from an image captured by a camera, receives an image size data, and according to the received image size, displays the captured image on the display device so that a code extracting target area is discriminated from a remaining area. A layout of the captured image on a display screen becomes flexible, so that usability for reading the code can be improved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromprior Japanese Patent Application No. 2005-310968, filed Oct. 26, 2005,the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a code reader device for reading a codesuch as a bar code or a two-dimensional code, and a recording medium.

2. Description of the Related Art

Conventionally, a code reader device for reading a code, such as a barcode or a two-dimensional code, captures the code by an image sensorsuch as a charge coupled device (CCD) or a complementary metal-oxidesemiconductor (CMOS), displays the captured image with a frame on adisplay screen such as a liquid crystal display (LCD), detects the codewithin the frame, and decodes the detected code. In order for the codereader device to properly read the code, a user adjusts a shootingdirection, with the help of the frame displayed on the LCD, such thatthe code is located within the frame.

For example, in Jpn. Pat. Appln. KOKAI Publication No. 2005-4642, as atechnique similar to the code reader device described above, there isdisclosed a mobile phone having a camera function, comprising a displaydevice which displays a captured image, a frame displaying device whichdisplays a frame on the captured image, and a bar code extracting devicewhich extracts a bar code image from the inside of the frame on thecaptured image.

However, with the camera-equipped mobile phone, it is difficult toarrange a layout flexibly on a display screen such that the capturedcode is displayed with an enlarged size, and an area indicating thedecoded information or operation information is displayed with a reducedsize. In other words, there is a problem that a usability of this kindof camera is not satisfactory.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided acode reader device which extracts a code from an image and decodes thecode, the image including a code extracting area and a remaining area,the code reader device comprises:

an image size specifying unit which specifies a display size of theimage, prior to extracting the code from the image; and

a display unit which displays the image with the display size specifiedby the image size specifying unit such that the code extracting area isdistinguished from the remaining area.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentinvention and, together with the general description given above and thedetailed description of the embodiments given below, serve to explainthe principles of the present invention in which:

FIG. 1 is a front perspective view of a code reader device 1;

FIG. 2 is a rear perspective view of the code reader device 1;

FIG. 3 is a schematic block diagram showing an electric configuration ofthe code reader device 1;

FIG. 4 is a schematic block diagram showing an electric configuration ofa camera 11;

FIG. 5 is a flow chart showing an operation of code reading processingin the code reader device 1;

FIG. 6 is a flow chart showing an operation of preview displayprocessing in the code reader device 1;

FIG. 7A is a flow chart showing an operation of frame position settingprocessing in the code reader device 1;

FIG. 7B is a flow chart showing an operation of a modified example ofthe frame position setting processing;

FIG. 8 is a flow chart showing an operation of a modified example ofpreview display processing shown in FIG. 6;

FIG. 9A is a table of setting data for each size of a preview image;

FIG. 9B is a view showing sizes of the preview image in comparison to adisplay screen;

FIG. 10A is a view showing examples of adjustment for the angle of viewin the captured image;

FIG. 10B is a view showing examples of displaying the captured image foreach angle of view;

FIG. 11A is a view showing expansion or reduction of an extraction area;

FIG. 11B is a view showing movement of the extraction area; and

FIG. 12 is a view showing a display example of displaying the codeextracting target area differently from the remaining area with respectto the luminance.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of a code reader device according to the present inventionwill now be described with reference to FIGS. 1 to 12. The presentinvention is not limited to the embodiments and terms used forexplaining the embodiments are not limited to the terms in the followingdescription.

First, an external configuration of a code reader device 1 is described.

FIG. 1 is a front perspective view of a code reader device 1. The codereader device 1 is provided as a camera-equipped portable terminal suchas a camera-equipped portable phone (cellular telephone) or acamera-equipped personal digital assistance (PDA). The code readerdevice 1 includes a display device 14 in an upper half of its front faceand an input device 15 on the other area of the front face and on aright side surface. The input device 15 includes a power key 15 a, atrigger key 15 b, and other various function keys 15 c includingalphanumeric keys for inputting numbers 0 to 9 or characters such asalphabets, and cursor keys. The input device 15 outputs a key operationsignal to a CPU 10 described later with reference to FIG. 3. A pluralityof charging terminals 16 a are provided at the lower end of the mainbody of the code reader device 1 for charging power to a power source 16which is an incorporated secondary battery described later withreference to FIG. 3.

FIG. 2 is a rear perspective view of the code reader device 1. The codereader device 1 includes a camera 11 provided at an upper part of itsback face. The camera 11 is a digital camera with a built-in opticalimage sensor such as a charge coupled device (CCD) or a complementarymetal-oxide semiconductor (CMOS). A battery cover 16 b is provided atthe back face of the code reader device 1 for opening and closing abattery housing unit that houses a secondary battery as a power supply16 described later with reference to FIG. 3. A fixing member (lock knob)15 c which fixes and releases the battery cover 16 b is provided at anend part of the battery cover 16 b.

Subsequently, an internal configuration of the code reader device 1 isdescribed hereinafter.

FIG. 3 is a schematic block diagram showing an electric configuration ofthe code reader device 1. As shown in FIG. 3, the code reader device 1is composed of a central processing unit (CPU) 10, the camera 11, arandom access memory (RAM) 12, a read only memory (ROM) 13, the displaydevice 14, the input device 15, and the power source 16, and thecomponents are interconnected to each other via a bus.

The CPU 10 uses the RAM 12 as a work area, expands a variety of controlprograms or setting data stored in the ROM 13 into the work area, andsequentially executes the programs, thereby controls each unit anddevice of the code reader device 1.

Specifically, the CPU 10 carries out operational processing describedlater, on the basis of the operating programs stored in the ROM 13. Theoperational processing of the CPU 10 is carried out as follows. Prior toextraction of a code from a captured image, a size for displaying thecaptured image is specified, and a code extracting target area (decodearea) is displayed according to the specified size so that the targetarea is discriminated from remaining area on the captured image. Thecode extracting target area is a target of code decoding processing onthe captured image.

The camera 11, as shown in FIG. 4, comprises a sensor unit 111, anoptical system driver 112, a driver circuit 113, an image sensor 114, ananalog processing circuit 115, an A/D circuit 116, a buffer 117, asignal processing circuit 118, a compressing/decompressing circuit 119,an optical lens 120, and a shutter 121. Image data captured by the imagesensor 114 is output after converted into a predetermined format inresponse to an instruction from the CPU 10.

The sensor unit 111 is composed of, not shown in particular, a distancemeasuring circuit with an infrared-ray projector and a receiver, and anexposure measuring circuit with a photoconductor such as CdS. The sensorunit 111 outputs a distance value and an exposure value of an imagecapturing object located within an image shooting direction to the CPU10.

The optical system driver 112 drives the optical lens 120 or the shutter121 by means of a stepping motor, an electromagnetic solenoid, or thelike. According to an instruction from the CPU 10 depending on thedistance or exposure value obtained by the sensor unit 111, the opticallens 120 is moved so that an image formed on the image sensor 114 isfocused on the image capturing object, and the exposure is controlledwith the shutter 121 in order that a quantity of light incoming to theimage sensor 114 becomes proper.

The driver circuit 113 sequentially captures charges generated byphotoelectric conversion for each pixels of the image sensor 114 as animage signal, and sends the signal to the analog processing circuit 115.The image sensor 114 is composed of an optical sensor such as a CCD or aCMOS, and outputs an image formed on an imaging area of the imagesensor, as an image signal corresponding to each pixel.

The analog processing circuit 115 includes a correlated double sampling(CDS) circuit which reduces noise in the image signal, and an automaticgain control (AGC) circuit which amplifies the image signal. The analogprocessing circuit carries out required analog signal processing ontothe image signal input from the image sensor 114, and outputs the analogimage signal to the A/D circuit 116.

The A/D circuit 116 converts the analog image signal input from theanalog processing circuit 115 into a digital image signal, and outputsthe converted digital image signal to the buffer 117. The buffer 117temporarily stores the digital image signal, and sequentially outputsthe signal to the signal processing circuit 118 orcompressing/decompressing circuit 119 in response to an instruction fromthe CPU 10. It is possible to output the digital image signalcorresponding to a predetermined area, which is extracted by specifyingan address pointer of the stored digital image data, from the buffer117.

The signal processing circuit 118 includes a digital signal processor(DSP), not shown in particular. The signal processor circuit 118 carriesout image processing such as luminance processing, color processing, anddetection of an object (detection of a code) in the captured image onthe basis of predetermined threshold value, to the input digital imagesignal. The image processing may include calculating sharpness of apredetermined area of the image so as to output the calculated sharpnessinto the CPU 10. In this manner, the CPU 10 can adjust a position of theoptical lens 120 in a focused state in which the sharpness becomesmaximal and a contrast becomes high.

The compressing/decompressing circuit 119 compresses and decompressesthe digital input image signal with a predetermined encoding scheme, andoutputs the resulting signal to the CPU 10. Both of a lossless or lossycompression/decompression system may be used. For example, AdaptiveDiscrete Cosine Transform (ADCT), or conversion to Joint PhotographicExperts Group (JPEG) image using Huffman encoding processing, which isan entropy encoding scheme, can be acceptable.

The optical lens 120 adjusts a lens position by the optical systemdriver 112, and forms (focuses) an image of a capturing object onto animaging area on the image sensor 114. The optical lens 120 may beconfigured to adjust an angle of view by adjustment of lens allocationwith the optical system driver 112 using a plurality of lenses, and toenable optical zoom. This angle-of-view adjustment using the opticallens 120 is explicitly described as “the optical zoom” in order todiscriminate it from a description relating to an angle of viewdescribed later. With respect to the shutter 121, a plurality of shuttervanes (not shown in particular) are located between the optical lens 120and the image sensor 114, and the shutter vanes are driven by theoptical system driver 112, thereby a quantity of passing light can becontrolled.

The display device 14 comprises a display screen composed of a liquidcrystal display (LCD). The display device 14 displays an image on thedisplay screen by required display processing according to displaysignals input from the CPU 10. The display screen is not limited to theLCD. The display device may be composed of another display element whichcan be built in a portable terminal.

The input device 15 has the power key 15 a, the trigger key 15 b, andother various function keys 15 c such as cursor keys, as shown in FIG.1, and outputs a key operating signal to the CPU 10. The input device 15may include a rotating body such as a dial key or a rotary trackballwhich outputs a rotational position of a rotating body as an operatingsignal, other than the operating keys. In particular, in order toinstruct a level of increase and decrease, such as expansion andreduction, or in order to instruct a moving direction such as up, down,left or right direction, it is preferable to accept the operatinginstruction from the rotating body.

The power source 16 supplies electric power from a battery power source(not shown) into each unit and device of the code reader device 1 inresponse to an instruction from the CPU 10 or an operation of the powerkey. The battery power source houses a built-in secondary batteries suchas a nickel-cadmium accumulator, a nickel-hydride battery, or a lithiumion battery. In addition, the built-in secondary batteries can becharged by a charger connected to the plurality of charging terminals 16a. The battery power source is not limited to the secondary battery, andmay be primary batteries such as an alkaline dry battery or a manganesedry battery.

Subsequently, an operation of code reading processing in the code readerdevice 1 is described with reference to a flow chart shown in FIG. 5. Asshown in FIG. 5, in step S11, the camera 11 performs initializationthereof including movement to an initial position of the optical lens120 and shutter 121, and resetting of the buffer 117. Next, the flowgoes to step S12 in which preview display processing is executed todisplay a captured image on the screen, prior to the extraction of acode from the captured image.

Details of the preview display processing in step S12 is shown in FIG.6.

When the preview display processing is started, a size of a previewimage on a display screen is set in step S31 according to an instructionfrom the input device 15, as shown in FIG. 6.

In a data table shown in FIG. 9A, a width and a height of the previewimage to be displayed are set for each size of the preview image. Thedata table stores setting data of an image size (display area) for eachzoom size (angle of view), and setting data of a code extracting targetarea (width and height) in the preview image, as size informationrequired for zoom size setting processing to be described later. Thedata table is stored in advance in the ROM 13 shown in FIG. 3.

A selection screen is displayed for size selection of a preview image onthe basis of size information such as 4/9 VGA (Video Graphics Array),1/4 VGA, 1/9 VGA, or 1/16 VGA stored in advance in the data table shownin FIG. 9A. When a user inputs a selection instruction from the inputdevice 15, size information data corresponding to the instruction isread out to the RAM 12, and the size of a preview image (an image area)is set. Then, in step S32, coordinates of a preview image display area,i.e., coordinates of the four corners of the display area are set inaccordance with the predetermined data or the user operatinginstruction.

In accordance with the size of the preview image set by the processingdescribed above, image display is performed as follows. That is, asshown in FIG. 9B, a preview image G is displayed when VGA is set, apreview image A1 is displayed when 1/9 VGA is set, a preview image A2 isdisplayed when 1/4 VGA is set, and a preview image A3 is displayed when4/9 VGA is set. Accordingly, to check the code to be decoded, a previewimage can be displayed in a large size. In the case of displayinganother information such as a resultant of the decoding, a preview imagecan be displayed in small size. In this manner, the display size of thecaptured image can be selected according to the type of usage. Thus, theusability is improved. Further, because a starting position of the imagedisplay can be set by the user, it becomes more flexible to arrange thescreen layout.

Next, in step S33, setting a frame display is executed to display aframe for distinguishing a code extracting target area from theremaining area. In step S34, setting of a zoom size (angle of view) isexecuted in accordance with data stored in advance or the operatinginstruction by the user. A selection screen is displayed for selectingthe zoom size (angle of view) stored in the data table shown in FIG. 9A.When the user inputs a selection instruction from the input device 15,accordingly the zoom size is set. As shown in FIG. 10A, in the casewhere ×1.0 is set, a preview image A11 is extracted, in the case where×1.5 is set, a preview image A12 is extracted, and in the case where×2.0 is set, a preview image A13 is extracted, from the entire imagingarea including a code C. As shown in FIG. 10B, the extracted zoom imageis displayed on the screen.

In step S35, setting processing for displaying the frame is performed.The frame is displayed in order to distinguish a code extracting targetarea from the remaining area. Details of the setting processing fordisplaying the frame in step S35 is shown in FIG. 7A.

When the frame display setting processing is started, the followingprocessing is executed as shown in FIG. 7A. That is, an input operationfrom the input device 15 is acquired (step S51), and it is determinedwhether frame expansion or reduction is instructed (step S52). Whenexpansion is instructed, display position data of the frame is set to avalue corresponding to the expansion (step S53). When reduction isinstructed, frame display position data is set to a value correspondingto the reduction (step S54). Subsequently the processing terminates.

The frame expansion/reduction setting is performed in such a way thatthe size data of the code extracting target area, and the size data ofthe imaging area in the image sensor 114 corresponding to the codeextracting target area, not shown in particular, are converted into thedata corresponding to the instructed expansion/reduction (refer to FIG.9A).

Due to the frame display expansion/reduction setting processing, asshown in FIG. 11A, the frame area, which is a target area of the codeextraction, indicated by a code extracting boundary frame W in thepreview image A before the setting, is expanded as in the preview imageA21, or reduced as in the preview image A22.

The frame display setting processing can be modified as shown in FIG.7B. That is, an instruction indicating a moving direction by the cursorkey or the like from the input device 15 is acquired (step S61), and thedisplay position of the frame is determined on the basis of the acquiredmoving direction and a distance corresponding to a key depressing timeor the like (step S62).

The setting for the movement of the frame display position isperformed-in such a manner that the position data of the code extractingtarget area, and the position data of the imaging area in the imagesensor 114 corresponds to the code extracting target area (both are notshown), are processed to be shifted based on the instructed movementdirection and distance.

By the setting processing for the movement of the frame displayposition, as shown in FIG. 11B, the area of the code extracting targetcan be moved to an arbitrary location in the displayed captured image(In FIG. 11B, a preview image A32 shows the frame movement to theright).

As a modified example of the frame display setting processing, the frameexpansion/reduction processing and the frame position movementprocessing described above may be used in combination with each other.

Following step S35, an imaging size setting of the camera such as anoptical zoom is set (step S36). The frame setting data for each zoomsize is calculated based on the preview size, zoom size, and framedisplay setting, which are determined during the above-describedprocessing (step S37). An area corresponding to the setting zoom size isread out from the buffer 117, whereby the preview image is acquired(step S38). A frame is combined with the preview image based on thecalculated frame display data (step S39). The preview image is displayedon the screen of the display device 14 according to the setting size andposition (step S40). It is determined whether a termination of thepreview display is instructed with the operating instruction from theinput device 15 (step S41). When the termination is not instructed, thecurrent processing reverts to step S34. When the termination isinstructed, preview display processing is terminated.

The preview display processing shown in FIG. 6 may be modified asfollows. As shown in FIG. 8, step S37 is replaced by the calculation ofthe data representing an area in which luminance is changed, for eachzoom size (step S371). The calculation is performed on the basis of thepreview size, the zoom size, and the frame display position, or thelike. The position of the luminance change area is identical to the codeextracting target area. Moreover, step S39 is replaced by step S391 inwhich reduction of display luminance in the captured image except thecode extracting target area is performed, according to comparativeoperation between the data of the luminance change area and the data ofthe imaging area of the image sensor 114.

In the modified example of the preview display processing, as shown inFIG. 12, an ordinary preview image A41 can be replaced by a previewimage A42 obtained by reducing the display luminance outside the codeextracting target area. As a consequence, even under the situation inwhich a frame line indicating the boundary is tend to merge into anoutside scene (background), the code extracting target area can beeasily recognized.

Although the luminance of the code extracting target area may be reducedin reverse, it is preferable to reduce the luminance outside the codeextracting target area in order that the code extracting target area iseasily recognized. In addition to the luminance change, changing a colortone of the code extracting target area can be applied.

Now, an operation of code reading processing shown in the flow chartshown in FIG. 5 is described hereinafter.

As described above, when the preview display processing shown in stepS12 terminates, the flow then goes to step S13. In the step S13, a lensaperture (a focus adjustment may be included) of the camera 11 or thelike is set. In the next step S14, an imaging size of the decodingtarget (decode area) is set based on the predetermined values or theresultant setting values of the frame display position settingprocessing (step S35). That is, the imaging size is set according to thepredetermined data or the size and position data of the code extractingtarget area on the imaging area of the image sensor 114.

Next, in accordance with the setting of the imaging size, the image ofthe target area (decode area) set by the above-described processing iscaptured from the stored image in the buffer 117 (step S15). Image dataof the captured decode area is stored in a memory area in the RAM 12(step S16). On the basis of the stored image data, the decode area isdisplayed on the display device 14 to be checked (step S17). The,decoding processing for extracting and decoding the code from the decodearea is carried out (step S18).

Subsequently, it is determined whether or not the decode processing instep S18 is succeeded, namely, whether or not the informationrepresented by the code such as a predetermined character string isacquired by decoding (step S19). In the case where the information isnot acquired, it is determined whether or not a predetermined time iselapsed from the initialization of camera (step S20). When it isdetermined that the predetermined time is not elapsed, the flow returnsto step S15. When it is determined that the predetermined time iselapsed, or when the decoding is succeeded, the flow terminates. When itis determined that the predetermined time is not elapsed, the flow mayreturn to step S13.

As described above, according to the embodiment, prior to the codeextraction from the image captured by the camera 11, the code readerdevice 1 receives the display size of the preview image from the inputdevice 15 for displaying on the display device 14. In response to theimage size, based on the setting data stored in the ROM 13, the codeextracting target area is displayed on the display device 14 so as to bediscriminated with the remaining area of the captured image. Thus, thelayout of the captured image on the display screen becomes flexible, sothat the usability for the code reading can be improved.

The code reader device 1 displays on the display device 14 the frameindicating the boundary between the code extracting target area and theremaining area in the captured image, therefore it can be easy torecognize the code extracting target area.

The code reader device 1 may display on the display device 14 thepreview image such that the luminance of the code extracting target areadiffers from that of the remaining area. Accordingly the user canrecognize a difference between the displayed areas as a plane instead ofthe boundary line, thus it may be easier to check the code extractingtarget area.

The code reader device 1 adjusts the zoom size (angle of view) of thecaptured image by adjusting the extraction area from the imaging area inthe image sensor 114, and to display on the display device 14 thecaptured image subjected to the zoom size (angle of view) adjustment.Therefore, in the case of detecting the code from a wide range of thecaptured image, or in the case of locating the code precisely in thecode extracting target area, the display according to situations can becarried out in a suitable size.

In addition, the code reader device 1 specifies the size and positionfor the code extracting target area of the captured image according tothe instruction of the user from the input device 15, to adjust the codeextracting target area based on the specified size and position, and todisplay the adjusted target area on the display device 14 at a suitablesize and position. Therefore, when the user adjusts the code extractingtarget area, the adjusting status can be recognized on the screen.

The present invention is not limited to the above-described embodiments.The detailed configuration and operation of the code reader device 1 inthe embodiments may be modified without departing from the spirit of theinvention.

For example, the code reader device 1 may include, other than the RAM 12and the ROM 13, a hard disk drive (HDD), a nonvolatile memory, and amedia drive for an optical/magnetic storage media. The data fordisplaying the captured image such as the preview image size, the zoomsize (angle of view) of the preview image, the size of the codeextracting target area, the position of the code extracting target area,and the like may be stored in advance in the above-described storages,instead of specifying the data by the operation form the input device15.

In order to set the preview size, the zoom size, the frame displayposition and the like, instead of selecting the data from the valuespredetermined discretely, the code reader device 1 may calculate anintermediate value of the predetermined discrete values and smoothly setthe setting data based on the calculated values.

According to the present invention, the code reader device specifies adisplay size of the captured image, and displays a code extractingtarget area according to the specified display size so that the targetarea is discriminated from the remaining area. As a consequence, alayout of the captured image on the display device becomes flexible, sothat the usability for code reading can be improved.

While the description above refers to particular embodiments of thepresent invention, it will be understood that many modifications may bemade without departing from the spirit thereof. The accompanying claimsare intended to cover such modifications as would fall within the truescope and spirit of the present invention. The presently disclosedembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims, rather than the foregoing description,and all changes that come within the meaning and range of equivalency ofthe claims are therefore intended to be embraced therein. For example,the code reader device 1 is not limited to a portable terminal housing adigital camera or a handy terminal housing a digital camera. That is,according to another embodiment of the present invention, the codereader device 1 may be a portable phone (cellular phone) housing adigital camera or a personal digital assistant (PDA) housing a digitalcamera.

1. A code reader device which extracts a code from an image and decodesthe code, the image including a code extracting area and a remainingarea, the code reader device comprising: an image size specifying unitwhich specifies a display size of the image, prior to extracting thecode from the image; and a display unit which displays the image withthe display size specified by the image size specifying unit such thatthe code extracting area is distinguished from the remaining area. 2.The code reader device according to claim 1, wherein the display unitdisplays a frame on a boundary between the code extracting area on andthe remaining area.
 3. The code reader device according to claim 1,wherein the display unit displays the code extracting area with a firstluminance level and the remaining area with a second luminance level. 4.The code reader device according to claim 1, further comprising an angleof view adjusting unit which adjusts an angle of view of the imagedisplayed by the display unit.
 5. The code reader device according toclaim 1, further comprising an area size specifying unit which specifiesa display size of the code extracting area, and wherein the display unitdisplays the code extracting area based on the display size specified bythe area size specifying unit.
 6. The code reader device according toclaim 1, further comprising an area position specifying unit whichspecifies a display position of the code extracting area, and whereinthe display unit displays the code extracting area based on the displayposition specified by the area position specifying unit.
 7. A computerreadable recording medium to store program instructions for execution ona computer system, which is used as a code reader device which extractsa code from an image and decodes the code, the image including a codeextracting area and a remaining area, enabling the computer system toperform: specifying a display size of the image, prior to extracting thecode from the image; and displaying the image with the display sizespecified by the image size specifying unit such that the codeextracting area is distinguished from the remaining area.
 8. A portableterminal which extracts a code from an image and decodes the code, theimage including a code extracting area and a remaining area, theportable terminal comprising: an image size specifying unit whichspecifies a display size of the image, prior to extracting the code fromthe image; and a display unit which displays the image with the displaysize specified by the image size specifying unit such that the codeextracting area is distinguished from the remaining area.